Method for pyrolytic conversion of petroleum oils



Nov. 7, 1933. F. A. HOWARD 1,934,067

METHOD FOR PYROLYTIC CONVERSION OF PETROLEUM OILS Filed OCC. 23, 1929INVENTOR ATTOR N EY Patented Nov. 7, 1933 PATENT oEEicE METHOD FORPYROLYTC CONVERSEON F PETROLEUM OILS Frank A. Howard, Elizabeth, N. J.,assigner to Standard Oil Development Company Application October 23,1929. Serial No. L101,661)

2 Claims.

This invention relates to the cracking of petroleum oils in equipmentcomprising a heating conduit discharging into a thermally insulateddigestion chamber or soaking drum. The pres-- ent application is acontinuation in part of my prior application Serial No. 202,191 led June29, 1927.

I have found that the conversion efficiency of such systems may bematerially increased and the formation of troublesome carbonaceousdeposits in the drum decreased by maintaining a local circulation in thedrinn.

The invention will be fully understood from the following description,read in connection with the accompanying drawing, in Which:

Fig. 1 is a `diagrammatic vertical section through equipment suitablefor carrying out my method, and;

Figs. 2 and 3 are views similar to Fig. 1 showing alternative forms ofthe equipment.

Reference numeral 1 in each gure designates a rebrick setting heated byany suitable means. Fresh oil is supplied through inlet pipe 2 toheating conduit 3, which consists preferably of a series of tubes joinedend to end by crossover connections to form a continuous circuit.Heating conduit 3 discharges through pipe 4 into digesting chamber orsoaking drum .5 surrounded by thermal insulation 6. 7 is a line for thecontinuous withdrawal of the cracked product, and is the only outlet forpermanent discharge of the product (vapor, liquid, or both) from thedrum. A pressure control Valve 'l' is installed in line y7. The crackedproduct is fractionated and condensed in any suitable Way.

Referring particularly to Fig. 1 a pipe 8 communicates with the soakingdrum at a point near the top thereof. A pump 9 may be operated tocontinuously draw oil through pipe 8' into pipe 10, which in turndischarges back into soaking drum 5.

Referring specifically to Fig. 2, a rotatable propeller 11 is attachedto shaft 12, actuated by motor 13. 14 is a stuffing box through whichshaft 12 enters the drum and 15 is a draft tube (Cl. 19E-51) to causethe material propelled to traverse a substantial part of the length ofthe drum to maintain the desired circulation.

Referring specifically to Fig. 3, a jet 16 is arranged to discharge theheated material from conduit 3 into drum 5. k17 represents a draft tubeor pipe and 18 a Venturi throat which, however, may be dispensed with.This form of the invention is generally to be preferred.

The circulation of oil and/or oil vapor in the drum is preferablycontinuous throughout the cracking period. Since methods of operatingcoil and drum installations of the type described are Well known (exceptas to the local circulation in the drum), no description of such methodsis required here.

While l have described my invention in conjunction vith certain specificforms of apparatus, it will be understood that it is not limited theretobut covers broadly `any cracking system in 5 which oils are caused toflotv under pressure in a continuous stream through a heating zone inWhich they are heated to cracking temperature and are subsequentlytransferred to a soaking or digesting chamber in which the temperatureis not raised and a positive local circulation oi the contents of thechamber is maintained.

WhatI claim is:

l. The process of cracking petroleum oil which comprises heating astream of the oil to a cracking temperature in an elongated narrowheating zone, passing the heated oil into a thermally insulated enlargeddigestion zone wherein cracking occurs, continuously conducting a streamof the oil Within the digestion` Zone from a part of said digestion zoneto another part, said stream being out of direct contact with the mainbody of the oil undergoing cracking, and continuously withdrawing all ofthe fluid products from the digestion zone in a single stream. 95

2. Process according to claim 1 in which the heated oil is dischargedinto the stream out of direct contact with the main body of oil yin thedigestion Zone.

FRANK A. HOWARD.

